Problem: If $x \boxdot y = 3y+4$ and $x \diamond y = (3-x)(y)$, find $3 \diamond (2 \boxdot 6)$.
Answer: First, find $2 \boxdot 6$ $ 2 \boxdot 6 = (3)(6)+4$ $ \hphantom{2 \boxdot 6} = 22$ Now, find $3 \diamond 22$ $ 3 \diamond 22 = (3-3)(22)$ $ \hphantom{3 \diamond 22} = 0$.